Currently, there are two lubrication methods for two stroke gasoline engines, i.e., the pre-mixing method, in which a given percentage of lubricant is mixed with the gasoline; and secondly the separating lubrication method, in which the lubricant is fed into the down-stream portion of carburetor by using an oil pump before being mixed with the atomized gasoline and then entering into the crankcase and the cylinder. According to the aforesaid two lubrication methods, the atomized fuel flows in a rather large space; the ratio of lubricant actually distributed on the friction surface between the piston and cylinder wall is very low; a portion of the lubricant remains in the cylinder and is not burnt completely. Upon being exhausted that portion of lubricant remaining in the cylinder causes the air to be polluted.